Furnace.



PATENTED MAY 5, 1903.

W. D. ZEHNDER.

FURNACE.

APPLIOATION PILBD OUT. 11, 1902.

3 SHEETSSHEET 1.

no MODEL.

lhiimssfs PATENT'ED MAY 5, 1903.

" W. D. ZEHN'DER.

FURNACE APPLICATION FILED our. 11, 1902.

30 MODEL.

Iii/1 114 RN 1 v .4 e9 'IIIIIIIIIIIIIIII zz 'IIIIIII w aoims PEIERS 00 PfioYoumo, wawmqou. n. cy

g UNITE STAT S Patented May 5, 1903.

ATENT FFIcE.

RNfw SEEGIFICATION forming part of Letters Patent No. 727,050, dated May 5, 1903. Application fiat October 11. 1902. semi No. 126,859. (no model! T0 to whom it may concern: I

Be it known that I, WILLIAM D. ZEHNDER, a citizen of the United States, residing in Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

The present invention relates to heatingfurnaces for usein the making of forgings and which are designed especially for the preliminary heating of iron or steel blanks preparatory to their subjection to-forging processes.

The present invention has for a principal object to furnish a heating-furnace of compact form andrelatively great capacity, and it involves, furthermore, a construction for furnaces of this character obviating quite,if

not entirely, the necessity of fire-brick or contact with the fuel and minimizing the destructive tenden'cyof the high heat of the burning fuel.

A further feature characterizing the present furnace is the provision in opposite walls of openings for the insertion from opposite sides of the furnace of the blanksto be heat ed, thus practically doubling the capacity of the furnace as compared with those constructions in which but one side of the fire only is used for heating the blanks. In the preferred construction also the furnace is selffeeding in operation, and the fuel prior to its arrival in the zone of incaudescence is preliminarily heated and more or less coked by the heated gases and products of combustion rising from the bed of fuel on the grate.

As regards the species of grate with which the present furnace is provided, this is preferably of the rocking type, while there is combined therewith a closed ash-box for permitting a blast to be applied upward through the grate and the bed of fuel thereon and which ash-box is capable of being opened for the purpose of discharging the refuse therein. It has been stated that a cooling and chilling medium is adapted to be circulated through the hollow walls surrounding the fire-box of the furnace, and in order to dissipate the heat taken up by such medium there is preferably comprised in a furnace made in accordance with the present invention and above the firebox thereof a tank or vessel open to the atmosphere and into which'the heated chilling medium, after its passage through the hollow walls, is discharged. A comparatively large surface of radiation is .thus exposed, facilitating evaporation, and in consequence materially assisting in the removal of the heat. 'A further advantage results from the exposure of a large surface of the heated medium to the air and its consequent comparatively rapid evaporation in that thereexists during the operation of the furnace a tendency to absorb sulfurous and other vapors given off zby the fuel, and thus prevent their diffusion through the air of the shop or room in which the furnace may be in operation.

The drawings which accompany the present specification clearly set forth the construction of the furnace.

In the drawings, Figure l is a side elevation of a furnace constructed in accordance with the present improvements. Fig. 2 is a plan view thereof. Fig. 3 is an end elevation looking from the right in Fig. 1. Fig. 4 is a similar view from the opposite end of the furnace. Fig. 5 is a vertical longitudinal section taken on' the plane corresponding to the vertical median plane of the furnace. Fig. 6 is a horizontal section taken immediately above the furnace-grate, and Fig. 7 is a transverse section taken on the plane of the line 7 7 in Fig. 1.

Similar characters of reference designate corresponding parts in all of the figures.

The furnace proper or fire-box and the parts associated therewith may be supported in any desired and appropriate manner, a table B being utilized for this purpose in the embodiment of the invention set forth in the drawings attached hereto. This table B comprises .in the construction illustrated side members I) b, end members b b, and a top plate or platform Z). This latter plate has a central opening within which the ash-box 2 depends, and around the opening above the plate I) the walls of the furnace proper or fire-box are disposed. One of the mostimportant features of the present improvements relates to the construction of these walls and the relative disposition of the surfaces thereof in contact with the fuel. In order to minimize the destructive tendencies of the burning mass upon the walls of the furnace, such walls are made hollow and adapted to have circulated through them a cooling medium, usually water, which takes up and removes the surplus heat. With regard to the disposition of the inner surfaces of these walls I preferto make them substantially vertical, as I find such disposition not only facilitates the feeding of the fuel, but also when the walls are so positioned and water is circulated through them there is little, if any, tendency to the formation of clinker, which ordinarily, when a fire-brick lining to the furnace is used, firmly adheres to the lining, necessitating more or less constant labor in dislodging it from the faces of the brick and interfering very materially with the continuous operation of heating the blanks. The material lying in contact with the chilled vertical walls has a tendency as the result of its being chilled to form a layer of ash in immediate contact with the walls, which overcomes the tendency of the fuel to stick to the sides and form clinker. Asto the material from which these Walls are best made I find excellent results follow from the employment of hollow iron castings. In the preferred construction,

moreover, the end and side walls are made separate from each other, thus producing a furnace or fire-box having separable walls,any one of whose parts in the event ofits becoming injured or impaired from the heatto which it is subjected may be removed and replaced by another without requiring the entire surrounding walls of the furnace to be replaced. In the organization shown and as a convenient means for supporting the separate parts of the walls, corner-posts, such as 3, are secured at the four corners of the furnace, a bottom flange 3' on each extending from the post and being bolted to the upper plate of the table. The end walls are designated by 4, each having an interior space t for the circulation of water, while the outer plate 4: of one end wall extends in this instance laterally and is clamped by bolts 4 to the corresponding corner-posts 3. For the convenient at tachmen t of these bolts such posts may each have a longitudinal T-slot, such as 4 \Vhile the end walls may each consist of a (the parting-line between the sections of each wall constituting the opening for the entrance of the blanks,) the side walls comprise sections which are adjustable relatively to each other, thus enabling the size of the opening through the wall to be varied. In the construction set forth each side wall 5 comprises an upper section 5 and a, lower section 5*. Means analogous to those employed for the assembling of the end wall may be used for the attachment of the sections of the side walls to the corner-posts 3, each post having in this instance upon its side face a T-slot 4 as before, with which may he engaged clamping-bolts, such as 5 passing through openings in lateral extensions of the outer plates 5 of the sections. By adjusting a section of each wall, ordinarily the upper section, the size of the opening 6 on that side may be readily varied. Each opening 6 preferably extends substantially the entire length of the furnace, and, as indicated, the upper boundary face of each opening is chamfered or beveled, (see 6,) and the lower boundary face along the upper edge of the lower section 5 is provided at short intervals with slight elevations 6 to facilitate the locating of the blanks thrust into the fire.

While the invention is not limited to the use of any particular style of grate, I have found in practice a grate of the rocking type to give good results. Such a species of grate is represented in the present drawings, the grate in its entirety being designated in a general way by G and comprising rocking grate-bars g, whose shafts g are supported at opposite sides upon ledges g, formed along the upper side edges ofthe ash receptacle or box 2. Means for rocking the bars of the grate maycomprise a longitudinally-reciprocative rod 8, pivoted to a lug 9, extending from the grate-frame and operable to and fro by means of a hand-lever l0, pivoted to the 'end of the rod 8 and having a pivotal support comprising apair of vibratory links 10, pivoted at one end to the lever and at the opposite end to a lug 10", extending from the supporting-table of the furnace.

The ash-receptacle 2, already adverted to, is preferably capable of being entirely closed at its bottom, as well as at its sides and ends, although for the purpose of dumping the ashes and refuse the bottom plate or closure is made to open, this latter portion 11 of the receptacle being in this case hinged (see 11) to the side of the receptacle, but being capable of being swung upward to close the bottom through the rotation of a rotaryoperatingrod 12, journaled in the ends of the supporting-table, and connected by means, such as a chain 12, with the free edge of the closure. This rod 12 is provided with an operatingcrank 12 and also with a toothed wheel 12 with which is adapted to engage a pivoted dog 12 to hold the closure in its elevated position. upward to close the ash-receptaclmthe exit When the bottom closure 11 is swung.

ing-table of the furnace.

for a blast passing into the receptacle is upward through the grate and the fuel thereon. In order, therefore, to supply a forced draft to the furnace, an'air-pressure conduit, suchthe furnace the operating-rod 12 is turned to permit'the closure-plate to drop the blast will obviously pass outward throught'he opening so made into the atmosphere, (the supporting-table of the furnace being of open construction to permit of this,) instead of forcing its way upward through the fuel. One of the uprights of the table may be provided, as indicated, with a door, such as 14, for the removal of the ashes, &c., droppedfrom the ashreceptacle.

The fuel is fed to the furnace gradually as its consumption progresses, passing down-. ward by gravity from a mass thereof located above the zone of incandescence. A hopper,

suchas 15, provides a convenient means for A further feature of the present heatingfurnace is directed to the preliminary heating of the fuel immediately prior to its arrival in the incandescent zone of the furnace. By thus subjecting the raw fuel to a preheating considerable volatilematter and substances, such as sulfurous fumes, deleterious in its action upon the blanks in the furnace, isevolved from the fuel, and the same may be, by means to be adverted to presently, carried off before cominginto contact with the metal. This preliminary heating of the fuel is accomplished in this instance by so organizing the parts that-the walls of the hopper 15 and its deliv ery-mouth are subjected to the action of the heated products of combustion and gases dur-- ing their passage outward fromthe furnace. In the construction illustrated the exterior side walls at the upper portion of the structure are formed by ribbed side plates 16 16, which are spaced some distance from the sides of the hopper and secured thereto by bolts 16 16, while the angularly-bent ends of these'plates are bolted to the ends-1717 of the upper struc-I ture, which ends are somewhat removed from the hopper ends 1717. The outtake for the der the floor, as usual in heating apparatus of this class. Such beingthe organization it is plain that theheated gasesarising from the fuel on' the grate before they escape encircle the hopper, thus subjecting the-fuel therein to a very'considerable' degree of'heat,

with the result that the more volatile matter,

together with a considerable portion of the sulfurous ingredients therein, are expelled. It is with the burning fuel thus preliminarily treated or coked that-the blanks come in contact; Gaseous products evolved in the'hopper pass through openings 2' to the exterior walled-in space.

As indicated-in Fig. 7 particularly, a space exists along the sides'of the furnacebetween the upper sections of the side walls ofthe furnace properand the laterally outwardly bent bottom edges 16 of the aforementioned plates 16. This space allows ample room for the adjustment of the upper sections of the side walls, as already explained, and toprevent the escape of gases through such spaces it is contemplated that they shall be filled in with fire-brick or cement.

For supplying the necessaryamount of cooling-water to the several hollowfurnace-walls any convenient arrangement of supply and discharge piping may be employed. Such pipes should be of a size suitable for-furnishing the requisite amount of water, having, due regard' to the pressure ofthe supply and the size and temperature of the furnacein any particular case. The system or arrangement ofpiping illustrated in the'drawings may be adopted, 'if desired, comprising a supply-pipe 18, located atone end of'the furnace and connecting with a branched supply 18 to the two lower sections 5 5 of the'side walls and also a branched supply-18 'tothe corresponding while the supply 18 passes inward 'to thehollow space within the end wall at the bottom thereof. At the opposite end-of the furnace an angle-pipe 18 connects the section 15 of one-of the side walls with the lower portion of the hollow interior of the end wal'l-t-hereat.

The water having circulated through the interior of the furnace-walls, instead'of passing direct to the outflow or discharge, is prefer-- cent to the furnace. such pan or tank by its exposure to "the atmosphereand evaporation not only serves to dissipate some ofthe heat, but performs a further-advantage in that the rising steam from'the fuel withinthe furnace. In the or A supply ably emptied into an open pan or tank adja The heated water in tends to absorb fumes and odors escaping ganization and-construction setforth thispan or tank (designated in-a general way by 19) is locatediat the upper portion of thefurnaoe,

covering the space between'the hopper and the sides and ends of the upper structure, and is of such proportions as to expose a comparatively large area of liquid to the atmosphere. The discharge-pipes to such tank lead from the wall-sections at points farthest removed from the localities at which the supply is delivered to such walls, and in the dischargepipingillustrated the end walls em pty through pipes 19 19, respectively, the upper section 5 of that wall from whose lower section the aforesaid angle-pipe 18 extends by a discharge-pipe 19 and the two sections of the opposite side walls by the discharge-pipe 19 An overflow-pipe w is also indicated.

In order to facilitate the breaking up of any clinker which may be formed within the body of the fuel on the grate, a poke-bar may be inserted through the openings 6 at the sides of the furnace, while additionally and for the same purpose a poke-opening 20 is formed in each end wall. Although such openings may be all that is necessary to give access to the bed of fuel on the grate in raking, cleaning, &c., the same, yet under some circumstances it may be advantageous to have greater freedom of access thereto. For this purpose one of the end walls may be made movable from its position at the end of the furnace. In the illustrated construction the end wall at the right is connected by hinges, such as 21, to the upper structure, adapting the wall to be swung upward, in which position it may be held by means such as a chain 22, which may be engaged with a retaininghook 22. The connecting supply-pipe 18 will then need to be of a flexible nature. For instance, it may consist of a rubber-hose connection, as may others of the connectingpipesfor instance, the pipe 19.

A furnace constructed and organized as indicated and described has been found to operate in a highly satisfactory manner using anthracite coalas a fuel, is singularly devoid of clinker, and hence may be kept for long periods in continued operation, is compact in form, and by reason of the fact that blanks may be heated from both sides has a relatively great capacity.

Having described my invention, 1 claim-- 1. In a blank=heating furnace, the combi nation of a fire-box, hollow metallic furnacewalls whose inner metallic faces constitute the fire-box walls in direct contact with the burning fuel, means for circulating a cooling medium through the interior spaces of the walls, a feeding-hopper fixedly secured to the furnace and extending downward into the fire-box, and an outtake for the products of combustion, one at least of said furnace-walls having openings for the introduction of blanks.

2. In a blank-heating furnace, the combination of a fire-box, hollow metallic furnacewalls whose inner metallic faces constitute the fire-box walls in direct contact with the burning fuel, means for circulating a cooling medium through the interior spaces of the walls, a feeding-hopper fixedly secured to the furnace and extending downward into the fire-box, and an outtake for the products of combustion, one furnace-wall and the oppositely-disposed furnace-wall each having openings for the introduction of blanks.

3. In a blank-heating furnace, the combination of a fire-box, hollow metallic furnacewalls com prising end and side walls separable from each other and whose respective inner metallic faces constitute the fire-box walls in direct contact with the burning fuel, means for circulating a cooling medium through the interior spaces of the walls, a feeding-hopper secured to the furnace and extending downward into the fire-box, and an outtake'for the products of combustion, one at least of said furnace-walls having openings for the introduction of blanks.

4. In a blank-heating furnace, the combination of a fire-box, hollow metallic furnacewalls comprising end and side walls separable from each other and whose respective inner metallic faces constitute the fire-box walls in direct contact with the burning fuel, means for circulating a cooling medium through the interior spaces of the walls, a feeding-hopper secured to the furnace and extending downward into the firebox, and an outtake for the products of combustion, one at least of the furnace side walls being sectional and at fording a space between the sections for the introduction of blanks.

5. In a blank-heating furnace, the combination of a fire-box, hollow metallic furnace, walls whose inner metallic faces are vertical and constitute the fire-box walls in direct contact with the burning fuel, means for circulating a cooling medium, through the interior spaces of thewalls, a feeding-hopper fixedly secured to the furnace and extending downward into the fire-box, and an outtake for the products of combustion, one furnacewall and the oppositely-disposed furnacewall being sectional and the sections of each wall being adjustable relatively to each other affording an adjustable space for the introduction of the blanks.

6. In a blank-heating furnace, the combination of a fire-box, hollow metallic furnacewalls comprising end and side walls whose inner metallic faces are vertical and constitute the fire-box walls directly exposed to the burning fuel and each side wall comprising an upper and a lower section adjustable relatively to each other to regulate the height of the intervening blank-introducing space, a feeding-hopper fixedly secured to the furnace and extending downward into the firebox, and an outtakefor the products of combnstion.

7. In a blank-heating furnace, the combination of a fire-box having separable and hollow end and side walls Whose inner faces are vertical, means for circulating a cooling medium through the interior spaces of the walls, and a feeding hopper terminating above the grate in the fire-box at a point sufficiently high to provide a proper depth of fuel on the grate, said hopper having an exterior walled-in space for the circulation of the products of combustion around it and the side walls comprising separated sections forming between them a space for the introduction of the blanks.

8. In a blank-heating furnace, the combination with a hollow-walled fire-box, of means for circulating a cooling medium into the interior spaces of the walls, andan open vessel through which the discharge from the interior of the walls is delivered.

9. In a blank-heating furnace, the combination with a hollow-walled fire-box, of means for circulating a cooling medium through the interior spaces of the walls, and an open vessel located at the top of the furnace.

10. In a blank-heating furnace, the combination with a hollow-Walled fire-box the inner faces of which are vertical, of means for circulatinga cooling medium through the intcrior spaces of the walls, and anopen vessel at the top of the furnace into which the discharge from the interior of the walls is delivered.

11. In a blank-heating furnace, the combination with a hollow-walled fire-box the inner faces of which are vertical and which comprises separate end and side walls, of means for circulating a cooling medium through the interior spaces of the walls, and an open vessel at the top of the furnace into which the discharge from the interior of the walls is delivered.

12. In a blank-heating furnace, the combination with a hollow-walled fire-box the inner faces of which are vertical and which comprises separate end and side walls, the latter of which are each made up of a plurality of sections, of means for circulating a cooling medium through the interior spaces of the walls, and an open vessel at the top of the furnace into which the discharge from their]- terior of the walls is delivered.

13. In a blank-heating furnace, the combination of a fire-box having hollow and separable walls whose inner faces are vertical, means for circulating a cooling medium through the interior spaces of the walls, a rocking grate, a feeding-hopper terminating above the grate in the fire-box at a point sufficiently high to provide a proper depth of fuel on the grate, said hopper having an exterior walled-in space for the circulation of the products of combustion around it, and an open vessel into which the discharge from the interior of the walls is delivered.

14. In a blank-heating furnace, the combination of a fire-box having separable and hollow end and side walls whoseinner faces are vertical, means for circulating a cooling medium through the interior spaces of the walls, a feeding-hopper terminating above the grate in the fire-box at a point sufficiently high to provide a proper depth of fuel on the grate,

said hopper having an eiz't'erio'r walledf-in space for the circulation or" the products of combustion around it and the side walls comprising separate sections forming between them a space for the introduction of the blanks, and means for introducinga blast upward through the grate.

15. In a blank-heating furnace, the combination with a hollow-walled fire-box the inner .faces of which are vertical and which comprises separate end walls and side walls made up of a plurality of sections, of means for circulating a cooling medium through the interior spaces of the walls, an open vessel at the top of the furnace into which the discharge from the interior of the walls is delivered, and means for introducing a blast upwardthrough the grate.

16. In a blank-heating furnace, the combination of a fire-box having hollow and separable walls whose inner faces are vertical, means for circulating a cooling medium through the interior spaces of the walls, a rocking grate, a feeding-hopper terminating above the grate in the fire-box at a point sufficiently high to provide a proper depth of fuel on the grate, said hopper having an exterior walled-in space for the circulation of the products of combustion around it, an open vessel into which the discharge from the interior of the walls is delivered, and means for introducing a blast upward through the grate. 17. In a blank-heating furnace, the combination of a supporting-table, corner-posts erected thereon, and separable hollow walls removably secured to said posts.

18, In a blank-heating furnace, the combination of a supporting-table, corner-posts erected thereon, separable hollow walls removably secured to slots in the posts, and means for circulating a cooling medium through the interior; spacesof the walls, the side walls being sectional. 7

1 9. In a blank-heating furnace, the combination of a supporting-table, corner-posts erected thereon, separable hollow walls removably secured to slots in the posts, the side walls being sectional, means for circulating a cooling medium through the interior spaces of the walls, and a feeding-hopper 'terminatnation of a supporting-table, corner-posts,

erected thereon, separable hollow walls removably secured to slots in the posts, the side walls being sectional, means for circulating a cooling medium through the interior spaces of the walls, a feeding-hopper terminating above the grate at a point sufficiently high to provide a proper depth offuelon the grate,

said hopper having an exterior walled-in space for the circulation of the products of combustion around it, and an open vessel on spaces for the introduction of blanks, a hopper above the fire-box having an exterior walled in space for the circulation of the products of combustion around it, means for circulating a cooling medium through the walls, an open vessel on top of the furnace into which the discharge from the walls is delivered, and an outtake above the lower end of said hopper for the products of combustion.

WILLIAM D. ZEHNDER. Witnesses:

FRED. J. DOLE, R. W. PITTMAN. 

